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* Sees core profit fall between 15 pct and 23 pct in 2013
* To pay dividend of 1.80 euros, to be approved in May 2013
* 2012 core profit 494 mln euros vs 481 mln expected
BRUSSELS, Feb 6 (Reuters) - Belgian mobile phone operator Mobistar said it will pay out less to shareholders in 2013 as it increases investment in faster mobile phone networks.
Mobistar, in which France Telecom has a 52.9 pct stake, is spending an extra 150 million euros on its fourth generation mobile data network, aiming to cover 80 percent of the Belgian population by 2015.
The group said on Wednesday will pay out 1.80 euros per share, to be approved by shareholders in May 2013, down from the 3.70 euros per share, which included an extraordinary dividend, it paid in 2012.
Core profit for 2012 fell 6.8 percent to 494.1 million euros ($668.44 million), meaning declines were narrower than a Reuters poll had forecast.
A total of 11 analysts polled by Reuters forecast on average a core profit of 481 million euros.
The group said the fall was caused by regulatory caps on tariffs and having to lower prices in the face of stiff competition.
Competition on the Belgian telecoms market increased in 2012 because of a new law forcing operators to limit customer contracts to six months, increasing the number of people switching operators.
For 2013, Mobistar expects revenues to decrease by 4 to 6 percent and core profit to come in between 380 and 420 million euros, a fall of between 15 and 23 percent. (Reporting by Robert-Jan Bartunek; Editing by David Cowell)